Checking if value is equal to DBNull in ParameterTarget to see if it has a DefaultValue is wrong on .NET Core

[einari]

The HasDefaultValue implementation is not working correctly on .NET Core.
The DBNull.Value check will in fact return true when it in fact does not have a default value.

By flipping it from != to == - I got the right result, but not sure of the implications of that.
Equally, the ParameterInfo coming in does in fact have a property called HasDefaultValue - wouldn't it be better to use this instead? Or is there something that escapes me?

[scott-xu]

Fixed